This invention relates to a method and a device for cleaning of a milk system, which is associated, for example, with a beverage maker.
For the preparation of beverages, such as, for example, coffee and chocolate, there are a multitude of devices available, ranging from manual system to fully automatic machine. The delicacies able to be produced using a beverage maker include drinks containing milk such as cappuccino, latte macchiato or café latte, requiring milk and/or milk foam for preparation. The milk is generally stored in a corresponding device, for example a milk container, which is integrated into a beverage maker or is associated with a beverage maker and is connectible thereto via a feed system. Starting from the milk container, the milk, via supply devices and possibly processing devices, is heated and foamed, for example, and, together with a coffee or chocolate drink, is dispensed at an outlet.
All elements which come into contact with milk in such a system must be cleaned regularly in order to fulfill the required hygienic standards. Thereby desirable is a possible automated cleaning process which is quick, safe and independent of operating personnel that leads to the desired reproducible cleaning result.
Known from DE 10 2014 215 689 is a device and a method for cleaning a feed unit for milk in a beverage dispensing device, whereby disposed in the feed unit, besides a milk container, are a cleaning agent tank filled with cleaning agent and an extraction pump connected thereto. For a cleaning mode, the milk container is replaced with a cleaning mixture tank into which the cleaning agent is transferred. In addition, or alternatively, fresh water can be led into the mixture container in order to provide a cleaning solution of a particular concentration or a rinsing solution for a cleaning mode. The cleaning solution is discharged and soiled system elements are rinsed by means of the feed unit of the beverage dispensing device.
Disadvantageous with this method is that the cleaning with cleaning agent and the rinsing with fresh water take place via the same mixture container. This requires time since, for example, the cleaning agent tank must first be completely emptied before a change of rinsing fluid is possible. Above and beyond this, a large quantity of fresh water is used. Furthermore the system does not provide for any checking as to whether a cleaning has in fact taken place. An unintentional contamination of the milk with cleaning agent can occur so that it is possible for a contaminated beverage to be prepared.
It is desirable to simplify the cleaning of a milk system associated with a beverage maker, of shortening the required cleaning time, of designing in a way that is reproducible for a user, of reducing the error proneness and of making possible a monitoring.
A method according to an aspect of the invention for cleaning a milk system, in particular associated with a beverage maker, is provided comprising the following steps, that first a milk container is replaced by a cleaning module having at least two zones, whereby cleaning fluid is filled in a first zone and in a second zone and a cleaning agent is filled in a chamber.
First and second zones are at least partially in fluid-conductive connection to one another depending upon the level of filling of the filled cleaning fluid. There follows a connection of the first zone and the second zone with docking units of the milk system for suctioning of cleaning fluid, conveying of the cleaning fluid through the milk system and leading back of the cleaning fluid into the cleaning module. After the connection, the milk system is rinsed with cleaning fluid, cleaning fluid being conveyed through the milk system out of the first zone and/or out of the second zone of the cleaning module. There follows a circuit rinsing of the milk system, cleaning fluid being withdrawn from the second zone, being heated by means of a heating device and being led back into the chamber, whereby it reaches the second zone via a fluid-conductive connection. The circuit rinsing is terminated after a predefined cleaning cycle. Afterwards there follows a final rinsing of the milk system with cleaning fluid which is withdrawn from the first zone.
Provided for, according to the invention, is that the cleaning fluid filled into the first and second zones is fresh water.
Through releasing of the cleaning fluid into a third zone or a drip tray, for example, which is already provided as an element of the beverage maker, the filling level drops in the second zone. If a predetermined low filling level is reached, a valve device of the second zone closes, and cleaning fluid, for example cold fresh water, is withdrawn from the first zone for the final rinsing.
This method combines in itself several advantages. In particular the first rinsing with fresh water can be carried out quickly, without heating capacity being applied. A heating device integrated in the beverage container is advantageously used in particular for the circuit rinsing, preferably a thick film heating element. This thick film heating element with its advantageous thermal characteristics makes possible a combined cold-hot cleaning method. Proven advantageous has also been a stepwise increasing concentration of cleaning agent in the cleaning fluid, so that an optimal cleaning can take place with simultaneous prevention of milk deposit and an effective elimination of milk fat. Furthermore, with the method and the device still to be described, a docking system of the milk container can also be cleaned from the outside in which milk deposits would otherwise remain. The circuit rinsing likewise saves resources.
It has proven advantageous that the switching between individual rinsing steps can take place without control. The switching over takes place according to the filling level, for example when the filling level of the cleaning fluid filled in the first and second zones has dropped in such a way that between the first and the second zone no fluid-conductive connection exists. Likewise a switching over to final rinsing takes place when the filling level causes a closing of the valve device in the second zone, which is preferably designed as float valve.
Provided for is that the existing milk container is replaced with a cleaning module according to the invention, the latter being pushed into a correspondingly designed housing so that in its final position the cleaning module is in fluid-conductive connection with provided docking units and further connecting means. The presence and exact position of the cleaning module can be detected by a mechanical, RFID, Hall, Reed or similar sensor and transmitted to a provided control unit in order to start the cleaning process. This automatic detection prevents a malfunction and is thus especially user-friendly.
Furthermore a monitoring can also be provided in order to verify that the drip tray, into which the cleaning fluid is conducted during the final cleaning, is removed and cleaned before the system is enabled again for beverage preparation.
At the beginning of the cleaning method according to the invention, a supply of cleaning fluid, in particular fresh water, takes place from at least one of the first and/or second zones of the cleaning module. At least a portion of the cleaning fluid from the first zone and/or second zone of the cleaning module is thereby suctioned in a first rinsing step. It is preferably provided for that first and second zones are at least partially connected in a fluid-conductive way. If the filling level sinks to a certain level during withdrawal of fresh water, the fluid-conductive connection between first and second zone is interrupted; the first rinsing step ends.
Alternatively valve devices can be provided in the fluid-conductive connections, which valve devices are opened and/or closed by means of a control unit in order to control the withdrawal of the cleaning fluid.
This phase of the cleaning method serves the purpose of thorough rinsing of the components to be cleaned whereby lacteal calculus accumulation is preferably prevented through cold fresh water, which accumulation is to be observed in particular with a rinsing with hot water. During this first phase, also referred to as pre-rinsing, in particular a portion of the stored fresh water is withdrawn and led out, whereby alternatively it can be led out into the drip tray or an existing third zone.
In a following step, the cleaning fluid withdrawn from the second zone is conducted in the circuit, i.e. it is suctioned from the second zone and led back into the chamber with the cleaning agent, from where it again reaches the second zone. When the led-back cleaning fluid arrives in the chamber, it absorbs the cleaning agent stored there. For example, stored in the chamber is a cleaning agent concentrate, in particular a cleaning tablet, which gradually releases cleaning components into the led back cleaning fluid. The concentration of the cleaning components in the cleaning fluid conducted in the circuit thereby changes, which cleaning fluid is also designated in the following as cleaning or rinsing solution. From the chamber, the cleaning or rinsing solution with a changed proportion of cleaning components reaches the second zone and forms there a reservoir of cleaning fluid. Through the conducting of the cleaning fluid into the chamber and a thereby accompanying dynamic flow movement, the cleaning components are thereby mixed advantageously with the cleaning or respectively rinsing solution, and in particular a cleaning component provided as a solid can dissolve to a large extent without residue.
The cleaning or rinsing solution conducted in the circuit can preferably be heated in this phase of the cleaning method by means of a heating element, preferably with a heating element based on thick film technology. In particular the cleaning or rinsing solution conducted in the circuit can be heated to a defined temperature, which, with a view to the hygienic effect to be achieved, amounts to at least 70° C. to 80° C. With the circulation of the cleaning or rinsing solution, this heating can be carried out in an especially energy-saving way. Moreover short cleaning times result in an advantageous way, during which cleaning times the milk system to be cleaned cannot be used in its normal operational mode.
In a further step of the cleaning method, the circuit mode is terminated, whereby the cleaning and rinsing solution is led into the existing third zone of the cleaning module or alternatively into the existing drip tray of the beverage maker. The third zone or respectively the drip tray thus provide a collecting container for the cleaning or respectively rinsing solution to be led out of the system and discarded. After a certain cleaning time, whereby the cleaning fluid is heated and, containing cleaning agent, is conducted in the circuit, the cleaning fluid is led into the third zone or respectively into the drip tray, whereby the fluid level in the second zone drops. Starting from a certain low fluid level, an existing valve device, preferably designed as float valve, closes off the cleaning fluid supply from the second zone, whereby automatically fresh water is suctioned out of the first zone, which fresh water is conducted into the third zone or alternatively into the drip tray. The existing heating element is switched off, so that the now lower temperature of the fresh water indicates a final rinse.
To check an obtained cleaning effect of the cleaning method, the conductance for the cleaning or respectively rinsing solution is determined. For this purpose, a conductance sensor is provided, preferably in the suction region of the pump, within the circuit of the cleaning or respectively rinsing solution, which sensor measures the actual electrolytic conductivity of the conveyed fluid and thereby gives information about the nature of the fluid or respectively its contamination level. Moreover it can be thereby verified which fluid is located in the pipe system. The conductance sensor can transmit signals to a control unit in order to indicate whether a cleaning operation has been successfully run. If the cleaning has been incomplete, in particular if the required standards of hygiene have not been met, the entire system can be blocked. This offers a reliable check for the operating personnel.
The method according to the invention comprises as means a cleaning module for a milk system with a dispensing device, which is associated with a beverage maker, in particular a coffee machine. Also understood thereby is an independent cleaning module, however, which is designed as stand-alone system.
The cleaning module according to the invention for a milk system with a dispensing device, for example a discharge head, comprises a cleaning container for receiving cleaning fluid, whereby the cleaning container has at least two zones. Furthermore the cleaning module has connection means, so that the at least two zones are connectible to the milk system in a fluid-conductive way such that cleaning fluid is able to be extracted, is able to be conveyed through the milk system and is able to be led back at least partially into the cleaning module. The compact cleaning module is easily manageable, so that also its cleaning can take place without any problems.
The milk system or respectively the beverage maker comprises at least in part a system of pipes or lines, at least one conveying device and a dispensing device, storage containers and possibly an air enrichment element as well as at least one heating element and a control unit.
With the cleaning module according to the invention, a cleaning of a milk system in connection with a beverage maker can take place, in particular a cleaning of those system components which are in direct contact with milk, whether they are supply devices, processing devices or dispensing devices for suctioning, conveying, preparing and dispensing of milk taken from at least one milk container. In particular it is also foreseen that interfaces, i.e. for example docking units and dispensing devices, are able to be cleaned both from the inside as well as also from the outside. Especially advantageous thereby is that the discharge head of a beverage maker no longer has to be disassembled in order to be cleaned since, according to the invention, it can be cleaned both from the inside as well as from the outside.
The cleaning module is connectible in a simple way to the milk system of a beverage maker; in particular, a milk container disposed in a housing can be replaced with the cleaning module. Existing connection and suction means for suctioning milk out of the milk container and conveying milk in the system of lines are connectible to the cleaning module in such a way that now a provided cleaning fluid is suctioned out of the cleaning module by the suction means and is conveyed through those system components of the milk system which are in contact with milk, and is at least partially led back.
In being exchanged with the milk container, the cleaning module can, for example, be inserted into the housing and can be connected to the connection means of the milk system in a fluid-conductive way. For example, the docking units provided within the framework of the milk system and possibly further existing connection means can be used e.g. for a leading back, whereby a flawless connection is facilitated.
The cleaning module has a plurality of zones, preferably a first and a second zone, which are at least partially connected to one another in a fluid-conductive way. In one embodiment, the cleaning module can comprise three zones, whereby preferably at least one of the three zones is designed as a separate and detachable container. Furthermore the cleaning module can comprise a detachable element on which the docking units and further connecting means are provided. This multipartite feature facilitates a cleaning of the individual parts of the cleaning module, as well as a replacement of individual elements, for example.
The cleaning module stores cleaning fluid at least in a first and in a second zone, whereby in the second zone a chamber is also provided in which a cleaning agent can be filled, and which is connected to the second zone in a fluid-conductive way. In a phase of the cleaning method, cleaning fluid can be led back into the chamber of the second zone, whereby this cleaning fluid overflows into the second zone and thus is able to be conducted into the circuit. After termination of the circulation phase, the cleaning fluid is collected, for example in the existing third zone, which provides a collection container for waste water, or alternatively in the drip tray. Preferably such a collection container is designed in a way that is detachable from the cleaning module, so that the cleaning fluid captured therein can be discarded.
Filled into the first zone and into the second zone of the cleaning module can be fresh water as cleaning fluid, and cleaning agent can be filled into the chamber at the beginning of the cleaning method. First and second zones are connected to one another in a fluid-conductive way at least partially, depending upon the filling level, or respectively separated from one another to the extent that there is pure fresh water in the first zone.
The cleaning module is preferably designed in such a way that, via a cleaning head connected to the dispensing device and a recirculation line into at least the chamber, the cleaning fluid at this dispensing device of the milk system is able to be led back into the third zone of the cleaning module or into the drip tray. The cleaning head is preferably designed in such a way that a rinsing of the dispensing device by the cleaning fluid is possible from the inside and from the outside. A cleaning head is thereby disposed on the dispensing device; for example it is connected thereto by means of magnets on the discharge side of the dispensing device. The disposed cleaning head is designed in such a way that the inside and outside of the dispensing device is preferably rinsed by a cleaning fluid in turbulent flow. Through the design of the cleaning head, an intensive cleaning is possible, whereby the cleaning fluid flows out of the dispensing device completely, for example through an outlet opening, provided at the lowest point of the dispensing device.
The cleaning module thus comprises at least two zones, designed, for example, as containers connectible to one another which can be filled with different media independently of one another. The media comprise fluids, for example fresh water or cleaning fluid, and/or solids, for example a cleaning tablet (cleaning tab). First and second zones are connected at least partially in a fluid-conductive way depending upon the filling level; for example first and second zones are partially separated from one another by a partition. The first and the second zone of the cleaning module are thereby in fluid-conductive connection to a suction side of the suction means, for example with the conveying device of the milk system. In particular the suction means comprise at least two fluid-conductive connections for the first and the second zone. The chamber and possibly the third zone are in fluid-conductive connection at least indirectly with the discharge side of the suction means.
The cleaning module comprises valve devices in the fluid-conductive connections of the first and of the second zones. Preferred are float valves which close depending upon the filling level.
First and second zones can be filled manually with cleaning fluid, preferably cold fresh water. A manual filling is advantageous compared with an automatic filling taking place within the milk system or respective in an associated beverage maker since at least no fresh water connection and further components have to be provided. Thus there exists a certain independence as regards the peripheral equipment. Furthermore a manual filling is able to be carried out in a shorter time than a filling by means of an integrated pump.
Stored in the chamber, formed in the second zone of the cleaning module, is a cleaning agent, for example in the form of a concentrate or respectively in the form of a cleaning tablet. The filling of the chamber with cleaning agent can likewise take place manually, which is less prone to error and is above and beyond that verifiable. This chamber is in fluid-conductive connection with the second zone of the cleaning module. Preferably the cleaning fluid is led back from the dispensing device of the milk system via the cleaning head connected there and the included recirculation line into the chamber of the second zone, whereby it is possibly enriched there with cleaning agent. In particular the cleaning fluid led back into the chamber reaches the second zone via a line or an overflow in order to be led in circulation during a phase of the cleaning method. This leading back or recirculation has proven to be especially water-saving.
Furthermore, in one embodiment, there is a recirculation line, having a valve, connectible to the third zone or alternatively to the drip tray so that recirculated, used cleaning fluid can be collected which is no longer fed into the recirculation cycle and is dischargeable in a simple way.
The cleaning module according to the invention is used to clean a milk system integrated in a beverage maker or associated therewith. A beverage maker is in particular a coffee machine, comprising at least one conveying device with a suction line on the suction side and an outlet line on the discharge side of the conveying device. Fluid is thus able to be suctioned via the suction line and is able to be conveyed via the conveying device and the outlet line to a dispensing device, designed in particular as a discharge head.
Moreover the device for cleaning can have furthermore valves, pumps, heating elements and/or a conductance sensor.